Why can t carbon 14 be archaeodated more than 50,000 years ago?

The half-life of carbon-14 is 5,720 years, which means that after 5,720 years, the amount of carbon-14 in dead plants is only half of the original, accounting for only one trillion parts of the total carbon. After two half-lives, i.e. 11,440 years, the amount of carbon-14 in dead plants is only half of what it was, or only one trillion parts of the total carbon.

So, this state-of-the-art antiquity dating technique, called carbon-14 dating, has some errors, and generally speaking, 5 to 10 percent errors are acceptable.

This method is good, but it has some inherent limitations. First, the age of the antiquities to be measured should not be too old, if the half-life of three carbon-14 is exceeded, that is, more than 17,000 years, and the carbon-14 content is less than one trillion parts, the measurement error will be very large, and it will be very unreliable to estimate the age.

The radioactive element dating depends on the determination of the relative abundance of the marker element, and the half-life of the radioactive element determines the applicable range.

C14 has a half-life of approximately 5128 years, memory.

The memory is wrong, hehe, it's 5730. Reference.

The half-life of C14 is 5730 years, which is half of the original defective bond after 5730 years. After 70,000 years, the amount of C14 is probably less than one thousandth of the original amount, and C14 is much less than C12, so that a small absolute error in measurement will cause a large relative error, with the existing technology, such a large error will make the measurement deviation very large, meaningless.

Also, it is generally believed that the C14 measurement method can only measure 50,000 years, and you say 70,000 years, but I don't know if the technology has advanced recently.

That's basically the above, the following is a copy, I hope it will help you too.

We know that there are three isotopes of carbon, 14C, 13C, and 12C

Among them, carbon 14 is formed by cosmic rays bombarding the outer layer of the atmosphere to obtain nitrogen atoms, and carbon 14 is oxidized to form carbon dioxide after formation, which enters the atmosphere, hydrosphere, biosphere and other spheres.

The semi-bright swim-life period of carbon 14 is 5730 years, that is to say, after 5730 years, the original content of carbon 14 is only half, and after 5730 years, there is only half of half left, although carbon 14 is constantly decaying, but new carbon 14 is also continuously produced in the outer layers of the atmosphere, which can basically "break even", so that the overall content of carbon 14 in the atmosphere remains unchanged carbonYou can imagine that plants absorb carbon dioxide through light and action, and animals eat plants and breathe. Therefore, the carbon in the body of every living life is always exchanged with the outside world, thus maintaining the basic level of the air.

Once a living organism dies, it can no longer absorb new carbon-14, and the carbon-14 in the body decays. As we mentioned earlier, the decay of radioactive elements is a function of time, and carbon-14 is no exception. Regardless of whether it is windy or rainy, after 5730 years, half of the carbon-14 decays into nitrogen and releases a particle (one electron).

So we can derive the age of death based on the amount of carbon-14 in the body of dead life. ,10,

The carbon-14 dating technique was invented by Libby of the University of Chicago shortly after World War II. RLB was a pioneer in radiological research at the prestigious Berkeley Laboratory in the United States. After a long period of research and experimentation, the carbon 14 dating technique was finally successfully created, and it was gradually accepted by archaeology and geology.

Since the Upper Paleolithic, this has become a powerful tool for determining historical epochs. For this, RLB was awarded the 1960 Nobel Prize in Chemistry.

In March 1949, when the journal Science published the first dating of radiocarbon, it immediately attracted the attention of the world's archaeology and geology. While people were amazed at this momentous scientific invention, they also expressed their respect and heartfelt gratitude to its founder, Professor Libby. However, carbon 14 dating technology is not absolute, and it has its own limitations that are difficult to overcome.

This limitation is mainly manifested in the fact that the age it determines is not precise, and there is generally a certain error.

On the one hand, the appearance of such errors is related to the age of the specimen. The older the age, the greater the error. On the other hand, it is also related to geographical differences, since the distribution of carbon on Earth is not absolutely balanced, which makes the comparability of chronological data in different regions different, and then related to the purity of the samples.

If the sample is contaminated, even if it is the residue of grass roots, the particles of bacteria, etc., it will affect the accuracy of carbon 14 dating. However, in this case, it can also be corrected with the tree's growth rings.

Despite such problems, carbon-14 dating remains the most widely used, effective, and reliable dating method in archaeology. At present, China has published thousands of archaeological specimens, and the accuracy of the determination is getting higher and higher, and its level has been among the highest in the world. In view of the unique and huge role of carbon-14 dating technology in archaeological research, the Xia, Shang and Zhou dynasties project has high hopes for carbon-14 dating technology.

It was invented by Libby of the University of Chicago shortly after World War II. RLB was a pioneer in radiological research at the prestigious Berkeley Laboratory in the United States.

The minds of archaeologists are not comparable to ordinary people, and many kinds of achievements are the result of their unremitting efforts

It was invented by Libby at the University of Chicago and used for military launches.

It seems to have been invented by the University of Chicago after World War II.

What is the principle of carbon 14 dating that is often used in archaeology? Time is determined by half-life.

a. The number of nuclear charges = the number of protons, if the number of nuclear charges is 6, the number of protons is 6; If the relative atomic mass is 14, then the number of neutrons is 14-6=8, so the option is wrong

b. According to the number of nuclear charges = the number of protons, the number of nuclear charges of carbon-14 atoms is 6, then the number of protons is 6, so the option is correct

c. According to the number of nuclear charges = number of protons = number of electrons outside the nucleus, the number of nuclear charges of carbon-14 atoms is 6, then the number of electrons is 6, so the option is correct

d. According to the relative atomic mass = number of protons + number of neutrons, the relative atomic mass is 14, so the sum of the number of protons and neutrons is 14, so the option is correct

So choose A

a. The number of nuclear charges = the number of protons, if the number of nuclear charges is 6, the number of protons is 6; If the relative atomic mass is 14, then the number of neutrons is 14-6=8, so the option is wrong

b. According to the number of nuclear charges = the number of protons, the number of nuclear charges of carbon-14 atoms is 6, then the number of protons is 6, so the option is correct

c. According to the number of nuclear charges = proton quiet number = the number of electrons outside the nucleus, the number of nuclear charges of carbon-14 atoms is 6, then the number of electrons is 6, so the option statement is correct.

d. According to the relative atomic mass = number of protons + number of neutrons, the relative atomic mass is 14, and the sum of the number of protons and neutrons is 14, so the option is correct

So choose A